SQL/MX Programming Manual for Java

Introduction

HP NonStop SQL/MX Programming Manual for Java—523726-003

1-4

SQLJ Compared With JDBC

SQLJ offers the following benefits as compared with JDBC programs.

Statically Compiled SQL

SQLJ programs typically use embedded SQL statements in SQLJ clauses for static

SQL and JDBC methods for dynamic SQL. SQLJ is intended to yield the performance

benefits of statically compiled SQL. Static SQL statements do not incur the cost of

compilation at execution time because you compile them during development. If

needed, you can use JDBC for SQL statements in an application, but SQL statements

in JDBC run dynamically. For more information, see SQLJ Versus JDBC Performance

on page 1-6.

Concise Programming Model

SQLJ offers a more concise programming model than JDBC. SQLJ automatically

generates the code that you must include in a JDBC program. Therefore, you do not

have to write as much code in an SQLJ program as you would in a JDBC program.

For example, in SQLJ, you can use host variables in an SQLJ clause:

#sql { INSERT INTO employee VALUES (:lastName,

:firstsName,

:deptNum,

:jobCode) };

In JDBC, you must individually set the value of parameters, which take the place of

host variables, in separate call statements, as this example shows:

Connection conn =

DriverManager.getConnection("jdbc:sqlmx:");

PreparedStatement stmt = conn.prepareStatement

("INSERT INTO employee VALUES (?,?,?,?)");

stmt.setString(1,lastName);

stmt.setString(2,firstName);

stmt.setInt(3,deptNum);

stmt.setInt(4,jobCode);

stmt.execute();

stmt.close();

In SQLJ, you can use both positioned and named iterators to retrieve rows. The

positioned iterator has a more concise style than the named iterator, which is similar to

the JDBC model for retrieval. For more information about iterators, see Iterators and

Result Sets on page 3-48.